<template>
  <div class="real-app">
    <input type="text" class="add-input" autofocus placeholder="接下去要做什么" @keyup.enter="addTodo">
    <item
     v-for="todo in filteredTodos"
     :todo="todo"
     :key="todo.id"
     @del="delelteToDo"
    ></item>
    <tabs :filter="filter" :todos="todos" @toggle="toggleFilter" @clearAll="clearAllCompeted"></tabs>
  </div>
</template>
<script>
import Item from './item.vue'
import Tabs from './tabs.vue'
let id = 0
export default {
  data() {
    return {
      todos: [],
      filter: 'all'
    }
  },
  computed: {
    filteredTodos () {
      if (this.filter === 'all') {
        return this.todos
      }
      const completed = this.filter === 'completed'
      return this.todos.filter(todo => completed === todo.completed)
    }
  },
  methods: {
    addTodo(e) {
      this.todos.unshift({
        id: id++,
        content: e.target.value.trim(),
        completed: false
      })
      e.target.value = ''
    },
    delelteToDo (id) {
      this.todos.splice(this.todos.findIndex(todo => todo.id === id), 1)
    },
    toggleFilter (state) {
      this.filter = state
    },
    clearAllCompeted () {
      this.todos = this.todos.filter(todo => !todo.completed)
    }
  },
  components: {
    Item,
    Tabs
  }
}
</script>
<style lang="stylus" scoped>
.real-app
  width 600px
  margin 0px auto
  box-shadow 0px 0px 5px #666

.add-input 
  positon relative
  margin 0px
  width 100%
  font-size 24px
  font-family inherit
  font-weight inherit
  line-height 1.4rem
  border 0
  outline none
  color inherit
  padding 6px
  border 1px solid #999
  box-shadow inset 0 -1px 5px 0px rgba(0, 0, 0, 0)
  box-sizing border-box
  font-smoothing antialiased
  padding 16px 16px 16px 60px
  border none
</style>

